Shifting device in a variable speed gearbox with pressure regulating valves for working and feed pressure

摘要

A gearbox of a gear-changing appliance has a frictional connection whose engagement by a hydraulic fluid actuator causes an associated gearbox transmission ratio to be effective. A control pressure derived from the working pressure of the actuator is used to influence a pressure regulating valve for a supply pressure present at a pressure regulating valve which adjusts the working pressure as required by an electronic control unit.